Subdivision Problem (2)

[shadowbuilt]

Greetings all. While following along with a video tutorial from Digital Tutors entiltled "Maya Intermediate Female Android Modeling," I ran into a slight problem. I'm hoping that someone here can help me out.
To make along story short(er), the process invovled using the 'create polygon tool' to create a profile view of the human face for the android. From there you extude the polygon face, delete the faces for the back and sides, and then extruding the edges to make the facial features. Then, you'd covert the polygons to subdivisions, and that's where I have a problem.
When I did the conversion, every edge that was extruded now ended in a flower petal shape. And there seemed to be a whole lot of extra geometry created. So, after trying 15 or so more times, I started experimenting. I made sure that I reset all of the tool settings, and even reset the user preference folder. And I still had the same problem.
Showing is better than telling, and here are some pictures to illustrate what's going on:

[img=http://img62.imageshack.us/img62/766/subd1wx1.th.jpg]

[img=http://img158.imageshack.us/img158/7759/subd2ih9.th.jpg]

[img=http://img231.imageshack.us/img231/1204/subd3eu3.th.jpg]

[img=http://img231.imageshack.us/img231/7592/subd4hy7.th.jpg]

[img=http://img209.imageshack.us/img209/5623/subd5cq7.th.jpg]

The first image is a default poly plane.
The second image is the plane with 5 edges extruded.
The third image shows the results of the poly to sub-d conversion. It seems to me that there is a good amount of extra geometry there, but I'm new, so I could be wrong.
The fourth image shows what happens when I select two edges and extrude them while in sub-d mode. The top extrusions have the vertices merged.
The fifth image is the same thing, bus with the 'keep faces together' option switched on. It's off by default.

So, my questions are:
1. Is it just me being stupid?
2. If it's not me then what could it be?
3. Is all that extra geometry necessary? This particular plane is still flat.
4. I also noticed that in the channel box for the extrude tools, there are values set for the x/y/z pivots and the taper. Should they be at zero? If so, how can I default them to zero?
5. Similarly, is there a way to make the 'keep faces togethe' option default to 'on?'

Before I forget, I'm using maya 7 unlimited, on Win Xp sp2.

Thanks in advance

[davesrose]

It doesn't look like you....that's what subDs are like in Maya! Why Does Digital Tutors say to use subDs? I like poly smooth proxy better.....you get more control that way. For SubDs, Maya does it's own thing for deciding which patches need more resolution. Alias never gave Maya very many SubD tools, so it still seems too rudamentary. I'm getting into XSI now, which has a much better system for SubD....you basically just go into the poly object's properties, say which subD method you want, then say how many subdivisions you want. Simple! Maya does all sorts of wonky things with subDs. My answer would be to never use them.

[joojaa]

Hah the fool that tries to make the other to follow

OK heiarchial subds have been muystified to death, and yes mayas implementation is realy hardcore. Too hardcore to meny users. (they dont wantr to know whats going on)

Anyway the petal shape is because you have the keep together option OFF. What this does it extrudes each edge seperately your just not seing it becaus ethey happen to overlap so it seems its perfect grid but your actualy having rtoo separate faces next to eachother.

OK now for the XSI user, who has misunderstood what the subdivision surface is about (but still free to use xsi if it floats his boat jisy dont talk bullshit). The purpose of the subd is to simulate the limitsurfavce of teh UNLIMITTEDLY much divided surface. As such maya can do the mak so and so divisions but maya truies to show you teh limit surface. Indeed the difference on screen is allmost nothing but if yu render this with a good renderer youll start to see it. Even xsi has this emaning but not all suers seem to get it because they dont have goodenough renderers.

Ok here:

Ok now the ones up there are the cage on division and 2 and then down theres a unlimitted amount of them. NOw see the hirarchial edits aside wich dont mcuh matter here theers no known prog that can show the limit on a realtime viewport so its divided. BUt soem renderers DO indeed show the limit heres the surface with 4 polygons per pixel... Indeed if i zoom in it never facets (bacause its still going to be 4 polys per pixel tahtks to one of the best renderers ever). THis si a very imporant whan you start to diplace stuff.

Anwyay im not realy going into wether its vbetter to have a smoothsurface as roepresentation or something like mayas. Who cares the target limitsurface si what your doing no matter how much you tust your eyes.

oh ps the image i by the way a remake of a old known demo image about the topic. Anyway at vido reslution it does not realy matter

[davesrose]

Well I have been a Maya user, but now that Autodesk is mucking with it, I'm trying to see what XSI's workflow is like. I merely am making the observation that it has seperate options for setting subD divisions for preview and render. It also will let you switch between catmulll or doo sabin subdivisions within its properties. That's pretty usefull, as they give quite different results.

I'll eat my crow about Maya's random subdivision levels:) I admit that I gave up on subDs when I was learning Maya, so I could have not known about sharing faces then. I found I didn't have problems with poly renders when my normals were well optimized and softened. I also found that working with scenes was faster, but could have been that when I was using SubDs, it wasn't well modeled with quads. You've convinced me to give subDs another shot Joojaa:)

[joojaa]

MAya has ptions for atleast 3 kinds of subdivisions yes.

[davesrose]

OK, now I'm totally confused and will just go ahead and act like a newbie (since I am when it comes to Maya's SubDs)....how do you change subdivision methods?? I'm trying out a basic SubD now. Only options I see for it in the editor is tessellation....uniform or adaptive. I'm trying to find answers on the net, and see a lot of threads about how XSI is better with subDs...stating Maya gets very slow when working in the scene file. Wonder if that's because XSI treats the subD as a node within the poly, and Maya tries to keep subDs seperated.

Also, just tried making a simple geometric shape, making sure the geometry was clean with all faces attatched etc. The display geometry is still dividing some areas and not others. Is that a display thing, and can you get it to represent a uniform subdivision? Including a shot of what it looks like in my preview. Can you recommend good sources for finding out more about Maya's subDs Joojaa? thnx

[joojaa]

The lines have nothing to do with subdivision amount mayas just pointing out that that area of the mesh is having a extra step to produce full quadrangulation of the mesh (thus also a ahigher hioiararchy area but you dont need to bother about that). The rest of teh areas still smooth. just ignore the lines, its just a preview of what yoyu get having it show n polygon divisions would not amke any mroe sense thatn taht eiher.

Its liek you dont realy care what the representation of teh nurbs surface is either.

Anway maya does not categoruize meshsmooths smooths as subdivision surfaces, while the orthers do. Yet in terms of how you think they still are (tehy arent but if you want to do a side by side comparasion they should be considered such just beacsue others say they are. So use smooth proxy wich more closly mimics what you expect)! So use smpoooth proxy wich is what teh representation of xsi often is.

Slowness... ah that ista misunderstanding people have with how they work, even polygons get slow in maya if you keep accumulating a unlimitted amount of history on top. They arent any particulary slower than on any other subd representation. Just the actual deal in interpolation.

Just because soemthing test a a lot o flack does not mean its broklen its jut alot of people who dont get it.

[davesrose]

well one thing I notice is that when I try changing the options for tesselation, it's not showing any difference in the preview. I suspect it's just changing the resolution of the divisions of the render right? If I did want to change how it actually divides (catmull or doosabian), can you do that natively, or do you need a plugin? When I try making the same object in XSI, I can get the exact representation using catmull.

Yes, I suppose I like poly smoothing because I'm more hands on! Since using Maya, I've much more been a Nurbs modeler. I've never had problems with seams as I've heard some people have had...could be just what they're doing. Before they had the edge ring tools, it was so much easier to do things with isoparms. I guess I also gave up on SubDs since Maya wasn't doing what I was used to (before Maya, I started with C4D...which was only good for SubDs). SubDs do have some cool tools, but it's also sometimes hard to figure out how it's going to say crease an edge. Anywho, for projects that require me zooming on a particular model, I'll keep Maya's SubDs in mind;)

[shadowbuilt]

Hey, thanks for the responses.
I did find the keep faces together option the polygon tools menu. I guess I missed it before while looking at the 10000 other menus and sub-menus.

[joojaa]

you can adjust screen smoothness in same ay as fore nurbs 1 2 3